Imaging devices such as an electronic still camera, a camera-equipped cell-phone and so forth are widely used. This kind of the imaging device takes a subject image with an image sensor of a CCD image sensor and so forth, and records obtained image data in a recording medium of a memory card and so forth. Some of the imaging devices are equipped with a flash unit (see Japanese Patent Laid-Open Publication No. 6-303504, for instance). The imaging device described in this Publication No. 6-303504 controls a flash-light amount in accordance with ambient light, which is applied to a subject, to prevent overexposure at a time when flash light is applied to the subject in addition to the ambient light.
The imaging device described in the above-noted Publication No. 6-303504 integrates an ambient-light amount with an external sensor. When the integrated amount has reached a prescribed level, flash emission is terminated to prevent overexposure. However, since a light receiving area of the external sensor corresponds to all of a shooting frame (predetermined angle of view) or to a central part thereof, the ambient-light amount integrated by the external sensor does not always indicate a correct status of the ambient light applied to a main subject, depending on a location and a size of the main subject taken within the frame. Thus, when the ambient light applied to the main subject is bright, overexposure of the main subject occurs. As a result, there arises a problem in that chroma clip of highlight is caused. In contrast, when the ambient light is dark (few), underexposure of the main subject occurs. As a result, there arises a problem in that the main subject is darkly taken.